Proper use of test kit

[Stryker]

Here is a good one.

You have your test kit, your testing for umm nitrates. Your vile has its water in it, chemicals added and now its turned a shade of red (whatever).

If you hold it agains the usual white test card you get it looks a lot darker owing to the 1-2mm of tube in contact with the card thus causes a kind of reflective shadow in the tube.

Hole the test tube 1-2mm away from the card and it looks a more even and natural shade, albeit a lighter shade.

I'd say the latter will yeild more accurate results....

I was just wondering on oppinion here esp as when reading nitrates it can make the difference of water appearing to be 20ppm or 40+ ppm !!

 

[Joviella]

i wonder this myself at every water test

 

[Bradder]

I wondered (agonized?) about this when I was cycling my tank. So I bought some "dip strips" and compared the readings over several tests. Looked like holding the vile 1-3 mm away from the card (as you say), in natural light, produced the most reliable results. Once I had a reliable reading, I then compared the color results under different lamps in my house to find the one I could best use for night-time testing. Was really amazed at the major "color shifts" that different night-time lighting, or even lamp shade reflections, gave me!

 

[noelberg]

good thread! it's funny how every test type has its pros and cons.
I like how the vile tests are a little more accurate than the dip strips , but they are tougher to read !

I know that electronic pH testing devices exist, but are there any that work for other perameters? They'd be more expensive for sure, but they'd also be much easier to use.

 

[Bangin]

I always look at the tube when it's a little distance away from the white card. The white throws the shade off, which makes it impossible to get an accurate reading.

 

[Stryker]

I wondered (agonized?) about this when I was cycling my tank. So I bought some "dip strips" and compared the readings over several tests. Looked like holding the vile 1-3 mm away from the card (as you say), in natural light, produced the most reliable results. Once I had a reliable reading, I then compared the color results under different lamps in my house to find the one I could best use for night-time testing. Was really amazed at the major "color shifts" that different night-time lighting, or even lamp shade reflections, gave me!

Superb idea, nice one. Regardless of dip test kit accuracy it seems to support the theory the vile tests are better compared a few mm from the test card.

Thanks

 

[Henry_VCG_]

good thread! it's funny how every test type has its pros and cons.
I like how the vile tests are a little more accurate than the dip strips , but they are tougher to read !

I know that electronic pH testing devices exist, but are there any that work for other perameters? They'd be more expensive for sure, but they'd also be much easier to use.

Normal test kits are expensive enough!
Although its good to know exactly what your levels are

 

[plateletboy]

I'm a molecular cell biologist so I can use a piece of equipment at work called a spectrophotometer to give me readings accurate down to 0.001ppm!!!

I'm also lucky enough to be able to make my own test kits. You would not believe how easy a nitrite kit is!! There is literally 5 pence worth of chemicals in a commercial one you would buy!! I can give you all the recipe if you can get hold of the chemicals!!

PB

 

[Henry_VCG_]

Wow thats great, I feel like a fool for spending so much dough on my test kit now

 

[noelberg]

Normal test kits are expensive enough!
Although its good to know exactly what your levels are

it depends on how much a piece of electronic equipment would cost. I have a feeling that the spectrophotometer is not cheap, plateletboy? but if you could market one for somewhere between $50-$100 then i'd gobble that thing up like a fat kid with cake.

many aquarium supplies are needlessly overpriced. $25 for a test kit, $3.40 for a little bottle of aquarium safe glass cleaner (just spray windex on a paper towel and wipe the glass!), etc. Just say "for your aquarium" and the value goes up.